1. Field of the Invention
The present invention relates to a directivity control apparatus, a directivity control method and a directivity control system which control directivity of sound data.
2. Description of the Related Art
In a related art, in a monitoring system provided at a predetermined position (for example, on a ceiling surface) of a factory, a shop such as a retail shop and a bank, or a public place such as a library, one or more camera devices such as a PTZ camera device or an omnidirectional camera device are connected to the system via a network to achieve a wide angle of view of image data (including a still image and a moving image, the same applies hereinafter) of a video in a monitoring target range.
Further, since the amount of information obtained by monitoring with a video is limited, a monitoring system in which sound data generated by a specific monitoring target such as a person present within the angle of view of a camera device is obtained using a microphone array device in addition to one or more camera devices is highly demanded. In such a monitoring system, in a case where an observer wants to listen to sound data generated by a specific monitoring target, it is necessary to establish synchronization between image data of a video captured by a camera device and sound data of a sound captured by a microphone array device.
Here, as the related art for establishing synchronization between the image data of video captured by the camera device and the sound data of the sound captured by the microphone array device, a signal processing device disclosed in JP-A-2009-130767 is known.
The signal processing device disclosed in JP-A-2009-130767 calculates a distance to an object captured by an imaging unit according to a result of a zoom operation of the object by a photographer, and emphasizes the sound collected by a microphone unit according to the calculated distance. Further, the signal processing device delays either of a video signal captured by the imaging unit or a sound signal collected by the microphone unit according to the distance to the object from the photographer. By doing this, since the signal processing device delays either the video signal or the sound signal according to the distance to the object even when the zoom operation is performed on the object by the photographer, the synchronization between the video signal and the sound signal can be achieved.